This invention relates generally to plastic containers having a lid, a base and a hinge joining the lid to the base.
Plastic containers have long been used to carry food from a cafeteria, grocery store or restaurant for consumption at another location. Such containers have typically included a base and a lid sized and shaped to matingly engage the edges of one another for securely enclosing food items prior to storing and transporting the items. These containers are commonly thermoformed from a sheet of thermoplastic material.
Some of these containers are manufactured, sold and used in two separate pieces as individual lids and bases. Often the lids and the bases are made of like shapes and sizes so that the lids and the bases may nest within one another when not secured to one another along their edges. A drawback to such two-piece containers is that they are inefficient to use as the lids corresponding to the bases must be matched and aligned to the bases prior to joining them to the bases.
Some plastic containers have overcome this drawback by hinging together the bases and the lids. These hinged containers are manufactured, sold and used as integral one piece units. The hinges of such containers are often comprised of one or more fold lines or creases in-between the lid and the base as shown for example in U.S. Pat. No. 5,860,549. The hinges allow the lid to be folded and unfolded repeatedly onto the base along the fold line. This efficiency of the one-piece container is particularly appreciated by persons involved in the packing of food into the containers as they are able to efficiently load food into the base without concern for later locating matching lids, and aligning the edges of the lids with the edges of the bases to close the filled container.
While solving the inefficiencies of the two piece containers, such one-piece containers have nevertheless created another drawback. In particular, one seeking to consume food packed in the container will commonly use the base of the container as a dinner plate. As such, the consumer opens the container by raising the lid to expose his or her dinner food placed upon the base. The lid of the opened container, although raised, nevertheless remains cumbersomely attached to the base. This is awkward as the lid may refold upon the base on its own. Even if it remains folded out the lid causes the container to consume twice the table space. Often such space is very limited as in airliners.
Recognizing this drawback, some users have attempted to remove the lid from the base with food contained in the base. One method of doing so requires scissors or a sharp knife to cut the hinge into two pieces thereby separating the lid from the base. Such cutting is extremely troublesome and dangerous as the plastic from which such containers are typically made is durable and difficult to cut, particularly while simultaneously trying to prevent food from spilling from such containers. Moreover, it requires a utensil that is not often present.
Accordingly, there remains a need for a plastic container that provides the advantages of having a base and a lid hinged together for manufacture, storage and transportation, yet without the disadvantage of remaining intact during consumption of its contents. It is to the provision of such that the present invention is directed.
The present invention meets the above-described need in the art by providing in a preferred form of the invention a plastic container having a base and a lid hinged together by a hinge. The hinge has a series of relatively thick sections joined together by a series of relatively thin sections. The thin sections are sufficiently thin to be severed upon an initial folding of the hinge. The thick sections are sufficiently thick to remain at least partially intact during the initial folding. With this construction, the container may be filled with product and closed with the hinge becoming partially severed and weakened and may be later opened with the hinge becoming completely severed to separate the base and the lid.
In another preferred form of the invention, a method of packaging and unpackaging food products comprises the steps of placing food in the base of an open plastic container having a lid and a base joined by a hinge, closing the lid onto the base and partially fracturing the hinge, and subsequently re-opening the container and completely fracturing the hinge thereby providing access to the product in the base with the lid unattached.